Apparatus for emulsion observation



March 30, 1954 w. c. GRIFFIN ET AL APPARATUS FOR EMULSION OBSERVATION 2 Sheets-Sheet l Filed July 3, 1951 A A A AA A n@ 4. .IA HIJ 2 I, Al 3 A w I Q I3 Il 9 a /8 In .n s mi I ln wm I I AIIIIHHIIH HHIHHIHIII IIIH nl L FIG. I

WILLIAM C. GRIFFIN March 30, 1954 w. c. GRH-"Fm ET AL APPARATUS FOR EMULSION OBSERVATION 2 Sheets-Sheet 2 Filed July 5, 1951 WILLIAM C. GRIFFIN,

Patented Mar. 30,Y 1954 APPARATUS FOR EMULSION OBSERVATION William C. Griin, West Chester, Pa., and Robert W. Behrens, Newport, Del., assignors to Atlas Powder Company, Wilmington, Del., a corporation of Delaware Application July 3, 1951, Serial No. 235,058

I Cl. 88-14) 2 Claims. l

This invention relates to laboratory apparatus,

and more particularly to an improved apparatus and emulsions for selected uses. When emulsions break cleanly into transparent oil and aqueous phases .the rate of separation 1s readily folservation.

It is the primary object of the invention to provide an improved apparatus for determining phase separation of emulsions by transmitted light and observing directly the relative proportions of separated layers.

Other` objects will become apparent in the course of the following description and the appended claims.

The essentials of the apparatus comprise a rack for vertically supporting tubes containing the samples to be examined, means for horizontally transmitting light selectively through tubes one tube at a time, light shielding means for cutting olf the transmitted light which does not This phenomeleast one side of said path, to which the position of the cream line can be referred for estimation of the relative proportions of the separated layers. 1

A specic embodiment of the apparatus of the invention is shown in the accompanying draw,- ings wherein,

Figure 1 is a front elevational view.

Figure 2 is a plan view, partly in section as indicated by the line 2-2 of Figure 1.

Figure 3 is a side elevation view in section along the line 3 3 of Figure 1.

In the several drawings like reference numerals refer to like parts.

The apparatus comprises generally a plurality of sample tubes I 9 supported in a rack I I, a lamp and housing therefor indicated generally by 3|, and a transparent scale plate 4I. The rack consists of end plates I2, joined to the ends of a base rail I3, and to the ends of front and rear upper rails Iii and i5, respectively. Behind the rear upper rail I5, two rods I 6 are positioned between covered slots I'l in the end plates, and held in position by nuts I8 threaded thereon. The said rods serve to support the lamp housing 33 to be described more fully hereinafter.

The vertical distance between the base rail I3 and the upper rails I4 and I5 is such as to expose a convenient depth of test emulsions for observation in sample tubes I9- which rest on said base rail and extend between the said upper rails. The sample tubes may be of any convenient size, preferably being not less than about a quarter of an inch nor more than about an inch in diameter. Tubes of approximately threeevenly spaced positions along said rack in slots formed by vertical spacer elements 2l (Figures 2 and 3), the opposite ends of which are fastened by any suitable means to the base rail and the rear upper rail. In the particular form illustrated, the lower ends of the spacer elements 2l are held by being extended through holes formed in the top of the base rail I3, and the upper ends of said spacer elements are soldered or welded to the rear upper rail I 5. The slots Zil are slightly less in width than the diameter of sample tubes I9, and spring members 22 mounted on the front upper rail I4 press the tubes firmly against said spacer elements throughout their vertical length.

In front of the tubes is scale plate 4I, supported between an upper channel 26, which is integral with the front upper rail I4, and lower channel 23, formed between the base rail I3 and the bent strip 24. The said strip is held in place glass, and carries a plurality of vertical scales, 42, etched, imprinted, or otherwise marked thereon. Conveniently, though not necessarily, these scales are divided in 100 parts as indicated in Figure 1 and each substantially traverses the vertical distance between thebase rail vand the front upper rail. In use, the scale plate preferably is adjusted vertically so that the base lines of the scales are in the same horizontal plane as the bottom of the liquid in sample tubes I9, resting vertically on base rail |3.

The length of the graduation lines of scales 42 is substantially the same as the width of the spacer elements 2|, and the scales are so positioned on plate 4| that they lie directly in front of said spacer elements, leaving clear, transparent vertical stripes in front of those portions of the tubes through which the spacer bars permit transmission of light.

Direct illumination for examining the contents of individual sample tubes by transmitted light is provided by the lamp and housing assembly designated generally by 3|. The source of light is provided by elongated, incandescent lila-ment electric lamps 32 of the clear glass type. These are mounted in a housing 33 depending from rods IB and in slidable connection therewith. The housing comprises vertical side walls 34, a iront wall 35, containing an elongated vertical slot 3S, approximating in length and width the openings formed by spacer elements 2| between the base rail I3 and rear upper rails l5. A curved reiiector 31 constitutes the back wall yof the said housing. Wired lamp sockets 38 are fastened to the end plates 39 of the lamp housing to receive lamps 32. A normally open switch 4G is included in electrical series with the lamps 32 and mounted on top of housing 33, whereby the lamps may conveniently be lighted only momentarily. It has been found that the stability of many test emulsions is affected by heat and, since the illumination required to make the cream line visible may be of heat producing intensity, provision for illuminating the tubes one at a time and only momentarily, ture of the invention.

The operation of the apparatus is nearly selfevident from its illustration and description. Samples of emulsions to be observed for phase separation rates are introduced into the tubes I9, the tubes being filled to a depth corresponding to the full length of the scales 42. At selected time intervals, as desired, the light source is brought into position directly behind the tubes individually, the switch 40 is contents of the tube observed for presence or absence of a cream line. If separation has occurred the fraction of the total represented by each phase may be readily estimated by reference to the adjacent scales 42 on either side of the illuminated tube. If the scales are graduated by 100 evenly spaced lines the fractions are readable directly in volume percent. The spacer elements 2|, against which the sample tubes are held rmly by spring members 22 serve as light shields to prevent distraction of the observer by illumination other than that through the test emulsion. Stray light is further cut down by the slot 3S in light housing 33 which is substantially as wide as the opening between the said light shielding spacer members. The cream line in a separating emulsion is much more readily discernible in the harsh light of a bare incandescent filament than lin the difuse lightpof .the usual, lugresentlisht tubesbr. .or frosted is a Very desirable feapressed and the 4 bulb incandescent filament lamps and the apparatus of the Ainvention is supplied with such a light source.

Quite unexpectedly it was found to be very important that scale plate 4| be ruled discontinuously producing a plurality of scales 42 rather than a single scale of graduation lines running the length of the plate. The presence of graduation lines across that portion of the plate directly illuminated through the sample tube while making an observation obscures the cream line completely in many instances and interferes with estimating its exact position in others. By placing the scales in the shadow of the spacer elements 2| this interference is eliminated. Light scattering by the translucent emulsion under observation directs sufficient light angularly outward to illuminate the graduation lines on either side of the tube under observation and, by alignment with said graduation lines the vertical position of the cream line in the sample tube is accurately estimable.

Variations in constructional details of the apparatus will readily suggest themselves to those skilled in the art, and apparatus embodying such variations is considered to come within the scope of the invention provided it accomplishes the same purpose by essentially the same method.

What is claimed is:

l. An apparatus for determining phase separation in emulsions which comprises a plurality of transparent sample tubes; a rack adapted to hold said tubes vertically in horizontally spaced relation; a vertically disposed, incandescent filament light source slidably mounted on said rack behind said tubes; light shielding means cooperating with said tubes and said light source to vconine illumination from said source to one of said tubes at a time as the said light source is slidably moved in its mounting behind said tubes; and a transparent plate supported by said. rack in front of said tubes, said plate bearing a plurality of vertical scales, said scales being spaced apart to leave unmarked transparent vertical bands registering with said sample tubes in the rack.

2. In an apparatus for determining phase separation in emulsions, a rack pre-viding receptacles for holding a plurality of tubes vertically in horizontally spaced relation; a vertically disposed light source slidably mounted on said rack behind said tube receptacles; spacer elements between the said receptacles which coniine illumination from said source to one of said receptacles at a time as the said light source is slidably moved in its mounting; and a transparent plate supported by said rack in front of said tube receptacles, said plate bearing a plurality of vertical scales spaced apart to leave unmarked transparent vertical bands registering with said tube receptacles in the rack.

WILLIAM C. GRIFFIN. ROBERT W. BEHRENS.

References Cited in the le of this patent 

